08 Fatboy, just done 800km. I noticed on the weekend that in 5th gear there is a bit of a rattle, once in 6th gear it seems to disappear. Does anyone know why this is happenig or what this could be?  I change into 5th gear when doing 80-90 and 6th gear at around 90-100

dont know? but i dont change to fifth untill im well over 100.

this was posted by fatboy-sirgarfield on another thread.

i dont go into 6 th unless doin 100 +

I just thrash mine, never get into fifth until 100 or 110 never go into sixth unless over 110
Some of em make a lot of noise in fifth but thats the nature of the beast I guess.
Mine is smooth in fifth but I do have this phantom squeal going on over 80 k's and the odd weird noise.
I only have 7444k's on it so far.
I have just ordered the true track stabilizers to make it corner a bit better hopefully stopping the sideways vibration may cure a few other things.

Easy fix , get ya'self a can of anti rattle , it worked for me ..................................

My 08 Heritage was the same. The different cut gears is a commonly recorded cause of the problem. Spoke to a mate of mine who has an engineering business and he cuts/exports gears for motorsports (off road, porsche, WRC, HDT and others). He said this is a common issue with straight cut gears, but can be "fixed". Cant recall what he said to do, but didnt do mine as I didnt want to bugger warranty. The noise has been described by someone somewhere as a coffee tin full of nuts and bolts. Mine sounded like absolute crap initially, particularly when coasting. Under load the whine stayed but the rattles disappeared. At first service I mentioned it to the stealer. Dont know what he did but it has gradually improved. Have only done 3200 km to date. Then  again the drop in noise may be just me getting used to it.  

This has been discussed in length before and is also a very high posting issue on other forums. The 5th hear is straight cut as stated and is the reason why. Appears that some make more noise than others. I've done 8000km on my 08RKC and it's not too bad. Actually I think it has improved with time/km's. Don't worry about it, it's the nature of the beast. I agree that the recommended gear change speeds seem a bit low.

I agree with twincam88b. There is a lot of concern about 5th gear noise in the 6 speed trannies in forums and mags. I've ridden 13,000kms on my 07 Fatboy and have never heard anything weird from any gear - each bike is unique I guess.

One thing my very experienced dealer emphasised from the start was change in the higher rev range rather than lower. Don't lug around under load at low revs. He reckons it will do no good at all. The older models maybe, but the newer ones will suffer over time. I don't use 6th at all under 100ks or so. Best to ride it hard. It's more fun and it's good for the scoot.

When I first rode mine, I thought the factory used the tranny out of an old tractor, the clunky changes were that bad. Now it's as smooth as silk. Must just wear in better over time.

heavy trans oil, only use 6th at 100kph+ the heavy trans oil will also help with any clunking when shifting from neutral to first. belray have a good oil for this

I have found that as the bike is loosening up the 5th gear sound is getting less noisey. It still makes a different noise compared to the other gears but 4000km's on it's okay I have learned to live with it.

Got 30k outa mine to now and don't notice the rattle at all, ya can also fix the rattle prob with louder pipes

Bt

I must be lucky..... all my gears are and have been smooth as..... the only rattle or ticking noise i got was from my exhaust (harmonics)..... and that took alot of finding... it did sound like something else when i first heard the noise.... and as you do when you get a new bike every new noise aint all good.... even though when you get your first service they recon they checked and tightened everthing.... well... i found quite a few things that were overlooked.... yes your gears might be noisey but its no waste of time to check other things too..... putting a spanner around my bike made a huge difference..... it feels and sounds better....

my 07 heritage has a strange noise in 5th gear ,has from new ,checked it out and was told it was normal,i use 6 over 100 ks,